Flexural modulus has standards in high impact polystyrene testing. This material is used in the manufacture of many plastics and rubbers. Plastics, like rubbers, should not be elastic or deformed. This causes a parameter called “Flexural modulus” to be set for the production of HIPS polystyrene.

In general, this determines the resistance of the polymer to deformation and elasticity. Flexural modulus is also different in different polymers. In addition, tensile modulus, torsional modulus, and shear modulus are also considered in the standards. In this PETROPROVIDERS article, join us to show you the measurement of Flexural modulus in HIPS polystyrene.

What is Flexural modulus and what does it do?

What is Flexural modulus

What is Flexural modulus

Flexural modulus is one of the properties of the material that indicates the resistance of the material to maximum pressure. This is also known as elasticity. It should be noted that to determine the flexural modulus, the maximum pressure of the material and its strength are used.

In mathematical diagrams, this parameter is displayed as a curve. The slope of this curve indicates the stress strain. This parameter is measured in Newtons per square millimeter.

One of the most important factors in determining module standards is the raw materials and production of that material. Polystyrene production methods are very diverse and there are various moldings for forming HIPS polystyrene. If the raw materials and production method of polystyrene are selected correctly, the cost of projects will be reduced and the quality of materials will be higher.

Introduction of effective parameters on Flexural modulus

One of the most important factors in measuring Flexural modulus is the energy between the atoms attached to the material. The stronger this energy, the higher the flexural parameter. This also increases the melting and boiling point of the material.

For example, if we increase the temperature of a substance, the motion of molecules in that substance will increase. This increases the partial motion of the atoms in the composition and reduces the energy required to separate these atoms. If this energy is reduced, the material bends easily; So we conclude that the elasticity of the material has decreased.

Introducing the standard test for measuring elasticity

standard test for measuring elasticity

standard test for measuring elasticity

In this test, we measure the overall resistance of the sample to pressure and deformation. This test is mostly performed on materials that are in the form of tubes or rectangles. It should be noted that in this test, all parameters affecting the Flexural modulus must be measured. This will result in inaccurate test results on the material and the quality of the materials produced will be higher.

The most important methods of this test are the three-point method and the four-point method. This test is performed by testing the tensile test device; The three-point method is the method that is more suitable for measuring the Flexural modulus in HIPS.

In this test, the software in the device measures the amount of force applied to the HIPS polystyrene sample and records it on a graph. The horizontal axis of this diagram indicates the amount of bending of the material and the vertical axis of this diagram indicates the force applied to the material. This test must be performed by ISO 178 and ASTM D790.

In the process of this test, the sample is first cut and transformed into the desired shape by injection molding. This material is then produced with a length of 20 times its thickness; It should be noted that the width of this sample is selected as desired.

For example, if the thickness of the sample is between 1 and 3 mm, its length should be set at 25 mm. Or if the thickness of the sample is between 3 and 5 mm, the length of the sample should be set to about 100 mm.

After this step, the sample is placed on two legs at a distance of 16 times the thickness of the sample. The force is then applied through the middle of the sample and the device measures the pressure diagram and the amount of bending of the polymer.

For samples smaller than 3 mm, the diameter of the bases should be 4 mm. For samples of 3 to 5 mm, the diameter of the bases is selected to be 10 mm.

It should be noted that the diameter of the input shaft is 10 mm. After placing the HIPS polystyrene inside the machine, this material is compressed at a speed of 1 mm per minute. This will cause the HIPS sample to bend. This method of measuring the Flexural modulus in HIPS is called the three-point method; Because the two bases are below the sample and the applied force is considered as the third point.

This sample is placed in the system and the force applied to it is calculated according to the following formula:

Flexural modulus Formula

Flexural modulus Formula

In this formula, the flexural strength is indicated by the sign Sigma. In addition, the Epsilon symbol is used to display the Flexural Modulus. In addition, other parameters of this formula are:

W = force applied

L = distance between test bases

b = sample width

d = Sample thickness

Summary of Flexural Modulus test on HIPS polystyrene

In this article, we saw the test and measurement of Flexural Modulus in high impact polystyrene. This test is performed to determine the resistance of the material to various pressures. This test must be performed by ISO standards. It should be noted that if this test is done correctly, the materials produced in the industry will be of higher quality.

HIPS polystyrene is used in the manufacture of many plastics in the industry as well as rubbers. Plastics, like rubbers, should not be elastic or deformed. This causes a parameter called “Flexural modulus” to be set for the production of HIPS polystyrene. This parameter will increase the quality of polystyrene materials.

What do you think about the Flexural Modulus test in HIPS polystyrene? Does this test show us the correct results? Is this test sufficient to determine the resistance of polystyrene material to different pressures? You can ask us your question about this test and the properties of polystyrene in the comments section. Contact our experts to buy the best polystyrene.